A ribbon coaxial cable of the type disclosed in U.S. Pat. No. 3,775,552 comprises a flat cable assembly of individually insulated conductors and drain wires sandwiched between layers of conductive shielding material, such as metal foil, and covered by electrical insulation material. Also disclosed are coaxial cables having a conductive metal shield surrounding the cable and a conductive drain wire within the shield, the shielded whole being covered by an insulating jacket or sheath. The center conductors and associated drain wires are said to be coplanar, precisely spaced and locatable in a common insulation layer where they can be easily found for termination of the cable following stripping or for mass termination by methods utilizing penetration of the common insulation and shielding layers.
Where closer spacing of the conductors was necessary, the drain wires were disposed between alternate pairs of conductors as shown in U.S. Pat. No. 4,234,759, and the drain wires were outside of the shields, but adjacent and touching two of them.
To improve such cables to solve problems of discontinuities and others attributed to flexing, torquing, vibration, etc., U.S. Pat. No. 4,588,852 disclosed the placing of a ground conductor inside the shield of each signal conductor adjacent the insulating material surrounding the signal conductor, then surrounding the shield with a layer of elastomeric material to ensure and maintain continuous electrical engagement of the drain and shield conductor along the length of the cable.